With the recent decline in outdoor spaces that are attractive and safe for children and young people, more and more cities, experts, scholars, and policy makers are focusing on child-friendly urban areas and are arguing, researching, and exploring them from different levels and perspectives. Over 20 years of playful urban design in Germany have provided a systematic framework for work on returning children and young people in urban public spaces. Through an in-depth analysis of playful urban public space planning and design instrument in Germany -master plan of play - the organizational structure and process of implementing a master plan of play in the old town of Regensburg, the participation of children and youth, the exploration of potential spaces and the development of playful public space design strategies are studied. It is concluded that diverse and continuous participation is the key to the practical construction of playful urban open space design. The key to the creation of active urban open spaces is the variety and continuity of participation. On this basis, the current situation of public spaces for children and youth in China is discussed, and the implications of the master plan of play and design for the development of playful urban open areas in China are explored to provide a reference for the creation of child-friendly cities.